Exception handling – PB Docs 2017

Errors that occur in the execution of a method of an EJB component
are mapped to exception proxies and thrown to the calling script. The
methods of all the classes in pbejbclient170.pbx can also throw exceptions
when, for example, connection to the server fails or the component cannot
be located or created.

Building EJB proxy projects generates the proxies for the home and
remote interfaces, proxies for any Java classes referenced by the EJB,
proxies for ancestor classes, and proxies for any exceptions that can be
thrown by the EJB and its supporting classes. The following exception
proxies are among those that may display in the System Tree:

Catching exceptions

A client application can handle communications errors in a number of
ways. For example, if a client connects to a server and tries to invoke a
method for an object that does not exist, the client can disconnect from
the server, connect to a different server, or retry the operation.
Alternatively, the client can display a message to the user and give the
user the opportunity to control what happens next.

When an error occurs, if the client connects to a new server to
retry the operation, it must instantiate the remote object on the new
server before invoking a method of the remote object.

In the following example, the script simply displays a message box
when a specific exception occurs:

Unhandled exceptions

If no exception handler exists, or if the existing exception
handlers do not handle the exception, the SystemError event on the
Application object is executed. If the SystemError event has no script, an
application error occurs and the application is terminated.